Thermoformed film belt freezer

ABSTRACT

The following paragraph is to replace the previous version of the abstract, and includes markings to show all the changes made relative to the previous version: 
     An apparatus and method for chilling or freezing a product includes a freezer having a freezing chamber therein in which a cryogenic substance is provided, and an inlet and an outlet in communication with the freezing chamber; and a plastic film belt constructed and arranged to transport the product from the inlet through the freezing chamber for exposure to the cryogenic substance to the outlet for removal of the product for further processing. The plastic film belt may be formed with one or a plurality of pockets to transport a corresponding amount of product.

The present invention relates to conveyor belts for transporting products for processing in such as for example a freezer or refrigeration unit.

Known freezing systems use a belt fabricated from stainless steel rods, drive links and wire to convey the products for processing, such as freezing or chilling. The construction of known belts and the materials used provide for many “trap points” for bacteria growth, such trap points known as “harborages”. Such belt construction has limited flexibility, cannot be molded to accommodate an exterior surface or entire shape of a product to be processed, and cannot retain cryogen substances to chill, freeze or crust freeze the product. Known belt also cannot hold liquid nitrogen (N₂) to be in contact with the product to be frozen. Additionally, such known type of belt permits products to stick to the belt, wherein the product is damaged, especially when the product is removed or separated from the surface of the belt upon conclusion of freezing. Moreover, such a known type of belt construction requires additional energy to cool the belt to the required operating temperature for transporting the product.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present embodiments, reference may be had to the following drawing figures taken in conjunction with the description of the embodiments, of which:

FIG. 1 discloses a top perspective view of a thermoformed film belt freezer embodiment of the present invention;

FIG. 2 discloses a top perspective view of another thermoformed film belt freezer embodiment of the present invention; and

FIG. 3 discloses a top perspective view of still another thermoformed film belt freezer embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The embodiments of FIGS. 1-3 use a plastic film, such as a polyethylene film, as a belt to be moved through a refrigeration unit, such as a tunnel freezer, to transport or convey a product such as for example a food product for processing. The present embodiments substantially reduce if not eliminate the product sticking to the belt.

One of the present embodiments provides for the plastic film to be thermoformed with a plurality or a myriad of pockets formed in the film in which product to be frozen is received in the pockets. Thereafter, the pocketed film is moved to the freezer wherein liquid cryogen such as for example liquid nitrogen, liquid carbon dioxide or other liquid cryogen, is dispensed such as by spraying the product disposed in the pockets. The plastic film may also be moved through an immersion bath in the freezer wherein the pockets are filled with the liquid cryogen for freezing the individual products in their respective pockets.

Alternatively, the plastic film can be used as a continuous loop. When extreme hygienic conditions are warranted, the plastic film can be used for a single pass through the freezer, after which the used plastic film is collected on a spool for either of destruction or recycling. Moreover, the plastic film can be used for a set period of time, such as one factory shift, or for a predetermined amount of product to be processed. Cleaning of the plastic film belt may not be necessary because the belt only has to be used for a single pass or limited passes through the freezer. The cost to fabricate the film belt is quite low compared to related steel constructions, and maintenance can be, in certain circumstances, completely unnecessary.

Referring to FIG. 1 there is shown a thermoformed plastic film belt freezer system embodiment 10. The freezer 10 includes a plastic film belt 12 which originates from a spool 14 or drum of the film belt 12 for transporting or conveying product 16, such as for example food product, through a freezer 18. The film belt 12 is returned to a take-up spool 20 or drum, whereupon the used film can be discarded, destroyed or removed for subsequent melting such as to recycle the film for subsequent use. Alternatively, the spool 20 can be omitted and the film belt 12 continues to the spool 14 as indicated by the broken line 22 such that the film belt 12 is a continuous loop transporting the product 16 to the freezer 18. The freezer 18 is provided with an inlet 17 and an outlet 19 between while a freezer chamber 21 is disposed. Cryogenic gas or liquid such as nitrogen or carbon dioxide is dispensed in the freezer chamber 21 to the product 16.

The product 16 is provided to the film belt 12 at a charging region for transport as indicated by arrow 24. The product 16 is conveyed through the freezer chamber 21 of the freezer 18, after which the frozen product is removed from the film belt 12 at a discharge region as indicated by arrow 26. A return run of the film belt 12 to the spool 20 or alternatively to the spool 14 is indicated generally at 28. Arrow 30 indicates the direction of movement of the film belt 12, while arrow 32 indicates a return run of the film belt 12.

Referring to FIG. 2 there is shown another thermoformed plastic film belt freezer embodiment 110. The freezer 110 includes a plastic film belt 12 which originates from a spool 14 or drum of the film belt 12 for transporting or conveying product 16, such as for example food product, through a freezer 118. The film belt 12 is returned to a take-up spool 20 or drum, whereupon the used film can be discarded, destroyed or removed for subsequent melting such as to recycle the film for subsequent use. Alternatively, the spool 20 can be omitted and the film belt 12 continues to the spool 14 as indicated by the broken line 22 such that the film belt 12 is a continuous loop transporting the product 16 to the freezer 118. The freezer 118 is provided with an inlet 117 and an outlet 119 between which a freezer chamber 121 is disposed. Cryogenic gas or liquid such as nitrogen or carbon dioxide is dispensed in the freezer chamber to the product 16.

The product 16 is provided to the film belt 12 at a charging region for transport as indicated by arrow 24. The product 16 is conveyed through the freezer chamber 21 of the freezer 118, after which the frozen product is removed from the film belt 12 at a discharge region as indicated by arrow 26. A return run of the film belt 12 to the spool 20 or alternatively to the spool 14 is indicated generally at 128. Arrow 30 indicates the direction of movement of the film belt 12, while arrow 132 indicates a return run of the film belt 12.

As shown in FIG. 2, the inlet 117, outlet 119 and freezer chamber 121 are constructed and arranged to receive both runs of the film belt 12. That is, upon depositing of the product 16 onto the film belt 12 for freezing, the film belt 12 enters the inlet 117 with the product 16 carried thereon to provide the product to the freezer chamber 121, after which the belt leaves the freezer chamber 121 by the outlet 119. Thereafter, the product 16 is discharged from the freezer 110 at 26, after which the belt is brought to a return run 128 in the direction of the arrow 132 such that the film belt 112 also moves during the return run through the outlet 119 into the freezer chamber 121 and then through the inlet 117 where it is collected on the spool 20 or alternatively the spool 14. In this manner of construction and operation, usually where the belt will be captured on the spool 14, the belt can be cooled or frozen on the return run 128 so that the temperature difference between the plastic belt 12 for retrieving the product 16 at the charging region 24 is not as great as it would be with the return run 128 exposed to the ambient atmosphere external to the freezer chamber 121, for example as shown in the embodiment of FIG. 1.

Referring to FIG. 3 there is shown a thermoformed plastic film belt freezer embodiment 210. The freezer 210 includes a plastic film belt 12 which originates from a spool 14 or drum of the belt film 12 for transporting or conveying product 16, such as for example food product, through a freezer 218. In the embodiment of FIG. 3, a thermoforming device 50 is arranged such that the film belt 12 passes therethrough. The device 50 forms a plurality and in many instances a multiplicity of pockets 52 in the film belt 12. Each one of the pockets is of sufficient dimensions to receive one of the products 16 or a plurality of the products dispensed from a dispenser device 54 disposed above the film belt 12. Each pocket 52 will receive one or a plurality of the products 16 therein for introduction into the freezer chamber 221 via the inlet 217. As that portion of the film belt 12 is conveyed through the freezer chamber 221, cryogenic liquid or gas is dispensed to contact the product 16 and also is retained or settled in each one of the pockets 16 to provide for increased freezing or crust freezing of the product 16 during its transport. Arrow 30 indicates the direction of movement of the film belt 12.

Thereafter, the film belt 12 departs the freezer chamber 218 through the outlet 219 whereupon the belt is collected on a take-up spool 56 or drum. In this manner of construction, the film belt 12 is used for one pass through the freezer chamber 221. Additionally, when the spool 14 of film belt 12 has been completely used, the film belt 12 is rolled up completely upon spool 56 for either permanent destruction or recycling into a form similar to the original form of the film belt 12 for reuse with the freezer embodiment 210. The frozen product 16 is released from the pockets 52 at the discharge region shown by the arrow 26 when the film belt 12 is collected upon the spool 56. Alternatively, once the device 50 has provided the pockets 52 in the film belt 12, the device can be removed and the film belt constructed and arranged as a continuous loop for movement around the spools 14,56 for use for a select period of time or until such time as the film is considered contaminated or less than optimal for freezing applications.

Regarding the thermoforming device 50, such a device is distributed by Multivac Inc. of Kansas City, Mo. U.S.A.

It will be understood that the embodiments described herein are merely exemplary, and that one skilled in the art may make variations and modifications without departing from the spirit and scope of the invention. All such variations and modifications are intended to be included within the scope of the invention as described and claimed herein. Further, all embodiments disclosed are not necessarily in the alternative, as various embodiments of the invention may be combined to provide the desired result. 

1. An apparatus for chilling or freezing a product, comprising: a freezer having a freezing chamber therein in which a cryogenic substance is provided, and an inlet and an outlet in communication with the freezing chamber; and a plastic film belt constructed and arranged to transport the product from the inlet through the freezing chamber for exposure to the cryogenic substance to the outlet for removal of the product for further processing.
 2. The apparatus of claim 1, wherein the plastic film belt originates from a spool of plastic film.
 3. The apparatus of claim 1, wherein the inlet, the freezing chamber and the outlet are sized and shaped to receive a portion of the plastic film belt.
 4. The apparatus of claim 1, wherein the plastic film belt further comprises a plurality of pockets formed therein, each one of said plurality of pockets sized and shaped for receiving one or a plurality of the product and the cryogenic substance within the pocket.
 5. The apparatus of claim 1, wherein the cryogenic substance is selected from liquid nitrogen and liquid carbon dioxide.
 6. The apparatus of claim 1, wherein the product is a food product.
 7. A method for transporting a product to be chilled or frozen, comprising: providing a plastic film belt of flexible material; forming a plurality of pockets in the plastic film belt, each one of the plurality of pockets sized and shaped to receive one or a plurality of the products therein for chilling or freezing; and providing a cryogenic substance to the plurality of pockets for contacting the cryogenic substance with the plurality of products to be chilled or frozen.
 8. The method of claim 7, wherein providing the cryogenic substance comprises spraying the cryogenic substance onto the product in the plurality of pockets.
 9. The method of claim 7, wherein providing the cryogenic substance comprises immersing the plastic film belt in a bath of the cryogenic substance.
 10. The method of claim 7, wherein the cryogenic substance is selected from liquid nitrogen and liquid carbon dioxide.
 11. The method of claim 7, further comprising melting and recycling the plastic film belt for subsequent use.
 12. The method of claim 7, wherein the product is a food product.
 13. A method of using a plastic film belt having a plurality of pockets formed therein for chilling or freezing a product disposed in any one of the plurality of pockets, comprising conveying the plastic film belt through a freezer for exposing the plurality of pockets to a cryogenic substance dispensed in the freezer, and releasing frozen products from the plurality of pockets of the plastic film belt. 